The present invention relates to a high density semiconductor device with reliable interconnection patterns. The present invention has particular applicability in manufacturing high density semiconductor devices with a design rule of about of 0.18 microns and under.
The escalating demands for high density and performance associated with ultra large scale integration semiconductor devices require a design rule of 0.25 microns and under, such as 0.18 microns, increased transistor and circuit speeds, high reliability and increased manufacturing throughput. The reduction of design rules to 0.25 microns and under generates significant challenges to the limitations of conventional interconnection technology, including conventional photolithographic, etching and deposition techniques.
Hydrogen silsesquioxane (HSQ) offers many advantages for use in interconnect patterns as a dielectric layer. HSQ is a highly desirable dielectric material. One form of HSQ is commercially available from Dow Corning Corp. under the product name Flowable Oxide(trademark) or FOX(trademark). However, the use of HSQ presents problems, particularly when plasma etching is conducted. When a photoresist mask is deposited and the through-hole is etched to expose a portion of the HSQ layer, the photoresist mask is then stripped, typically employing an oxygen O2-containing plasma Assessments of the feasibility of employing HSQ as a dielectric layer in interconnection patterns revealed that the O2-containing plasma employed to strip the photoresist mask degraded the HSQ layer.
HSQ typically contains between about 70% and about 90% Sixe2x80x94H bonds. However, upon exposure to an O2-containing plasma, a considerable number Sixe2x80x94H bonds are broken and Sixe2x80x94OH bonds are formed. Upon treatment with an O2-containing plasma, as much as about 20% to about 30% of the Sixe2x80x94H bonds in the deposited HSQ film remained. In addition, exposure to an O2-containing plasma increased the moisture content of the deposited HSQ film and its propensity to absorb moisture. An HSQ film having reduced Sixe2x80x94H bonds and high Sixe2x80x94OH bonds tends to absorb moisture from the ambient, which moisture outgases during subsequent barrier metal deposition. Thus, during subsequent barrier and metal deposition, outgasing occurs thereby creating voids leading to incomplete electrical connection.
In copending application Ser. No. 08/951,592, filed on Oct. 16, 1997, a method is disclosed for restoring degradation of an HSQ film by exposure to an H2-containing plasma to increase the number of Sixe2x80x94H bonds, to decrease the number of Sixe2x80x94OH bonds, and to decrease the propensity to absorb moisture. The disclosed treatment with an H2-containing plasma enables the use of HSQ to gap fill metal lines and form borderless vias with improved reliability by reducing outgassing and, hence, void formation.
In view of the manifest advantages of HSQ, there exists a need to provide technology whereby HSQ can be employed as a dielectric layer in forming interconnection patterns in a semiconductor device. There also exists a need to form interconnection patterns employing HSQ as a dielectric layer with improved reliability and increased production throughput.
An advantage of the present invention is a method of manufacturing a high density, multi-metal layer semiconductor device with a design rule of about 0.18 microns and under having an interconnection pattern comprising an HSQ dielectric layer.
Another advantage of the present invention is a high density, multi-metal layer semiconductor device with a design rule of about 0.18 microns and under and an interconnection pattern comprising an HSQ dielectric layer.
Additional advantages of the present invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from the practice of the present invention. The advantages of the present invention may be realized and obtained as particularly pointed out in the appended claims.
According to the present invention, the foregoing and other advantages are achieved in part by a method of manufacturing a semiconductor device, which method comprises:
depositing a layer comprising hydrogen silsesquioxane (HSQ) containing Sixe2x80x94H bonds on a first conductive pattern comprising a first conductive feature;
forming a first dielectric layer on the HSQ layer;
forming a second dielectric layer on the first dielectric layer,
forming a photoresist mask on the second dielectric layer;
etching to form an opening in the second dielectric layer leaving the first dielectric layer exposed; and,
removing the photoresist.
Another aspect of the present invention is a semiconductor device comprising a first metal patterned layer comprising a first metal feature;
an HSQ layer formed on the first metal patterned layer,
a first dielectric layer formed on the HSQ layer and the first metal patterned layer;
a second dielectric layer formed on the first dielectric layer,
an opening formed through the second dielectric layer, the first dielectric layer and the HSQ layer exposing at least a portion of the first metal feature and,
conductive material filling the through-hole to form a connection.
Additional advantages of the present invention will become readily apparent to those skilled in this art from the following detailed description, wherein only the preferred embodiment of the present invention is shown and described, simply by way of illustration of the best mode contemplated for carrying out the present invention. As will be realized, the present invention is capable of other and different embodiments, and its several details are capable of modifications in various obvious respects, all without departing from the present invention. Accordingly, the drawings and description are to be regarded as illustrative in nature, and not as restrictive.